Gordon, who pleaded guilty to unlawfully administering a poison or noxious thing with intent, screamed and refused to be led down to the cells after Judge Pamela Badley imposed the immediate jail term at Preston Crown Court.

Mr Moore, who suffers a range of difficulties including non-epileptic fits, made friends with Gordon and several other drivers on the Kendal to Lancaster route, on which he travels frequently.

Prosecuting, Jane Dagnall told the court the incident unfolded on August 15 last year as Mr Moore travelled to Lancaster, and that after taking a mouthful of the hazardous mixture, he later suffered a fit – though it can’t be proven if the concoction caused it.

Today the victim, who works restoring furniture for charitable organisation Oaklea Trust, said the most hurtful thing was Gordon’s taunting actions on the internet afterwards.

He said: “I was going to Lancaster on the bus and I told him I was thirsty. He had a bottle in his bag. I saw it looked green but he said it was lemon and lime.

“It had a Pepsi label on. He said I could try it. I trusted him. I swallowed a bit but it was not what I thought. He took it off me and laughed.

“I think some of the drivers carried detergent with them to clean the windscreen and floor.

“He took a picture of me holding the bottle and later on that day he posted it on Facebook like it was a joke. He took the Pepsi label off, to make me look silly.”